• IEMEK Journal of Embedded Systems and Applications
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• v.17 no.2
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• pp.109-114
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• 2022

This paper proposes a 2D joystick and LoRa-based teleoperation system for the Ackermman steering mobile robot. The proposed joystick mapping algorithm reduces the linear speed of the robot when the joystick is steered in the direction of the maximum steering angle in the high-speed driving state of a mobile robot to reduce the risk of rollover. The LoRa-based remote operation system is designed for remote operation of mobile robots that require long range communication with relatively little data transmission and low power. The proposed system is implemented and the experimental results demonstrate the effectiveness of the teleoperation system with respect to the stability of communication strength and the robot motion.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.325-329
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• 2003

In this paper. the stability and performance analysis of wave-based teleoperation system is presented. For stability and performance analysis with respect to the variation of characteristic impedance b, loop gains of communication channel and minimum value of trasmitted impedance from slave side to the master side are considered. The stability of slave side may be enhanced by increasing characteristic impedance b, whereas exssively high value of b may degrade the performance, which imply a tradeoff between stability and performance.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.3
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• pp.363-371
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• 2021

Forest operations like timber harvesting have already been mechanized to reduce hazards to the worker and increase productivity. However, timber harvesting operations have still been considered potentially dangerous and expensive on steep terrain. Teleoperation, to control the timber harvesting machine at a distance, has the potential to improve the safety, productivity and efficiency of harvesting operations on steep terrain. To verify the effects of teleoperation, an experimental prototype system of a monitor image-based teleoperation was constructed using a real forestry machine. In this study, the productivity of excavator based grapple loader, which is one of the most used mechanized harvesting equipment in the timber production, was analyzed using time-study method. Factors like skill and age of operators, influencing loader productivity in timber loading operation were also evaluated by statistical analysis. Productivity analysis results showed that less experienced operators were more productive than experienced operators for teleoperation through image of monitors in the operator cabin. These results are shown to be unfamiliar to the monitor image and different loading operation pattern by operators. According to the results, the monitor image-based teleoperation system of forestry machine need to improve the resolution and installation position of camera. It was expected that additional studies will be needed for real-time remote control of forestry machine in the future.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1470-1475
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• 2003

The senses that a doctor can feel is limited in MIS(Minimal Invasive Surgery) which guarantees the fast recovery of the patient and minimal incision for going in and out of instruments through the tissue of the patient. In particular, the surgical robotic teleoperation system developed recently serves with only the information of eyesight and auditory sense. Therefore force-reflection is the most demanded element of the senses in manipulating surgical instruments. In this paper, we designed the Master system and the 2 D.O.F grasper for the robotic teleoperation system(Slave) that has two force sensors on the grasper. Particularly, we focused on serve to master's handle with the contact force between tissue and the grasper of Slave.

• IEMEK Journal of Embedded Systems and Applications
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• v.15 no.2
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• pp.95-101
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• 2020

In situations where mobile robots are operated either by autonomous systems or human operators, such as smart factories, priority-based teleoperation is crucial for the multiple operators with different priority to take over the right of the robot control without conflict. This paper proposes a priority-based teleoperation system for multiple operators to control the robots. This paper also introduces an efficient joystick-based robot control command generation algorithm for differential-drive mobile robots. The proposed system is implemented with ROS (Robot Operating System) and embedded control boards, and is applied to Pioneer 3AT mobile robot platform. The experimental results demonstrate the effectiveness of the proposed joystick control command algorithm and the priority-based control input selection.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.5
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• pp.891-898
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• 2001

This paper develops a master manipulator which can reflect a force from a slave manipulator effectively. It many have a big workspace, can represent a human operators manipulation perfectly, and is composed of a position control part, an orientation control part and an end effector control part. This paper also develops a graphic simulator using the Visual C++ and OpenGL in the Window operating system. It can be used to make a virtual slave manipulator and set a virtual working environment, and provide a visual information from a desired view point. A virtual teleoperation system is developed by connecting the developed master manipulator to the graphic simulator using an interfacing hardware bilaterally. It is used for performing a virtual object exploration experiment. In the experiment, two virtual objects are used. They are virtual wall and virtual hexahedron which have 0.7N/mm and 2.2 N/mm stiffness respectively. The experiments are performed under six different working conditions. The experiment results will show the effectiveness of the reflected force from the slave manipulator for improving the efficiency and stability of the teleoperation task.

• 한국HCI학회:학술대회논문집
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• 2008.02c
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• pp.19-24
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• 2008

This paper presents a physically-based haptic rendering algorithm for a deformable object based on visual information about the intervention between a tool and a real object in a remote place. The physically-based model of a deformable object is created from the mechanical properties of the object and the captured image obtained with a CCD camera. When a slave system exerts manipulation tasks on a deformable object, the reaction force for haptic rendering is computed using boundary element method. Snakes algorithm is used to obtain the geometry information of a deformable object. The proposed haptic rendering algorithm can provide haptic feedback to a user without using a force transducer in a teleoperation system.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.116.2-116
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• 2002

$\textbullet$ Introduction $\textbullet$ Teleoperation System $\textbullet$ Stiffness Identification $\textbullet$ Frictional Characteristic Identification $\textbullet$ Conclusions

• International Journal of Aeronautical and Space Sciences
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• v.16 no.3
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• pp.463-474
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• 2015

Future Ground Control Stations (GCSs) for Unmanned Aerial Vehicles (UAVs) teleoperation targets better situational awareness by providing extra motion cues to stimulate the vestibular system. This paper proposes a new virtual environment for long range Unmanned Aerial Vehicle (UAV) control via Non-Line-of-Sight (NLoS) communications, which is based on motion platforms. It generates motion cues for the teleoperator for extra sensory stimulation to enhance the guidance performance. The proposed environment employs the distributed component simulation over GSM network as a simulation platform. GSM communications are utilized as a multi-hop communication network, which is similar to global satellite communications. It considers a UAV mathematical model and wind turbulence effects to simulate a realistic UAV dynamics. Moreover, the proposed virtual environment simulates a Multiple Axis Rotating Device (MARD) as Human Machine Interface (HMI) device to provide a complete delay analysis. The demonstrated measurements cover Graphical User Interface (GUI) capabilities, NLoS GSM communications delay, MARD performance, and different software workload. The proposed virtual environment succeeded to provide visual and vestibular feedbacks for teleoperators via GSM networks. The overall system performance is acceptable relative to other Line-of-Sight (LoS) systems, which promises a good potential for future long range, medium altitude UAV teleoperation researches.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.3
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• pp.243-249
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• 2015

In direct vehicle teleoperation, a human operator drives a vehicle at a distance through a pair of master and slave device. However, if there is time delay, it is difficult to remotely drive the vehicle due to slow response. In order to address this problem, we introduced a novel methodology of shared vehicle teleoperation using a virtual driving interface. The methodology was developed with four components: 1) virtual driving environment, 2) interface for virtual driving environment, 3) path generator based on virtual driving trajectory, 4) path following controller. Experimental results showed the effectiveness of the proposed approach in simple and cluttered driving environment as well. In the experiments, we compared two sampling methods, fixed sampling time and user defined instant, and finally merged method showed best remote driving performance in term of completion time and number of collision.